Fig. 4

Identification of the PR cleavage site in RIPK1. a Primary sequence of human RIPK1 (aa 449–476 according to NCBI Reference Sequence NP_003795.2) with PR cleavage site between residues 462 and 463. Indicated point mutations were introduced by Quikchange mutatgenesis. b HEK293T cells were transfected with expression plasmids encoding wild-type (wt) RIPK1, RIPK1 with a double-mutation in the PR cleavage site (RIPK1 PR^res), or RIPK1 with a non-sense mutation in the PR cleavage site (RIPK1 ΔC), respectively, along with catalytically active HIV PR (5 ng/well) in the absence (−) or presence (+) of SQV (5 μM). Cell lysates were subjected to SDS-PAGE and immunoblotting (WB). Proteins were revealed using antibodies against c-Myc, β-actin, or HIV-1 PR